Hello Kamil,
Monday, June 22, 2009, 12:01:40 AM, you wrote:
> Right... Python uses hashtables while here I have a tree with log n
you can try this pure hashtable approach:
import Prelude hiding (lookup)
import qualified Data.HashTable
import Data.Array
import qualified Data.List as List
data HT a b = HT (a->Int) (Array Int [(a,b)])
-- size is the size of array (we implent closed hash)
-- hash is the hash function (a->Int)
-- list is assoclist of items to put in hash
create size hash list = HT hashfunc
(accumArray (flip (:))
[]
(0, arrsize-1)
(map (\(a,b) -> (hashfunc a,b)) list)
)
where arrsize = head$ filter (>size)$ iterate (\x->3*x+1) 1
hashfunc a = hash a `mod` arrsize
lookup a (HT hash arr) = List.lookup a (arr!hash a)
main = do let assoclist = [("one", 1), ("two", 2), ("three", 3)]
hash = create 10 (fromEnum . Data.HashTable.hashString) assoclist
print (lookup "one" hash)
print (lookup "zero" hash)
--
Best regards,
Bulat mailto:bulat.zigans...@gmail.com
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